Fiber optic connector with fiber take-up region

ABSTRACT

A fiber optic connector assembly includes a connector and a carrier. The connector, defining a longitudinal bore extending through the connector and having a first end region and a second end region, includes a ferrule assembly, having an optical fiber extending through the connector, at least partially disposed in the longitudinal bore at the first end region, a tube, defining a passage and having a first end portion disposed in the longitudinal bore at the second end region and a second end region, and a spring disposed in the bore between the ferrule assembly and the tube. The carrier includes a cable end and a connector end engaged with the connector, a termination region disposed between the connector end and the cable end, a fiber support region disposed between the connector end and the termination region, and a take-up region disposed between the connector end and the fiber support region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/206,958, filed Jul. 11, 2016; which is a continuation of U.S. patentapplication Ser. No. 14/611,936, filed Feb. 2, 2015, now U.S. Pat. No.9,389,372; which is a continuation of U.S. patent application Ser. No.13/455,249, filed Apr. 25, 2012, now U.S. Pat. No. 8,944,702; which is acontinuation of U.S. patent application Ser. No. 12/849,633, filed Aug.3, 2010, now abandoned; which is a divisional of U.S. patent applicationSer. No. 12/433,081, filed Apr. 30, 2009, now U.S. Pat. No. 7,766,556;which is a divisional of U.S. patent application Ser. No. 11/735,267,filed Apr. 13, 2007, now U.S. Pat. No. 7,534,050, which applications arehereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to a fiber optic connector assembly, andmore particularly, to a field terminatable fiber optic connectorassembly.

BACKGROUND

The use of fiber optic networks as a signal-carrying medium forcommunications is now extremely widespread and continues to increase.Fiber optic networks frequently include a plurality of fiber opticcables having optical fibers. As fiber optic networks continue to grow,the need for optical fiber terminations for maintenance or expansionpurposes is also growing. As such, there is a need for an optical fibertermination which can be used in the field in order to terminate anoptical fiber or optical fibers.

SUMMARY

An aspect of the present disclosure relates to a fiber optic connectorassembly comprising a connector and a carrier. The connector defines alongitudinal bore extending through the connector and has a first endregion and an oppositely disposed second end region. The connectorincludes a ferrule assembly, which includes an optical fiber thatextends through the connector, at least partially disposed in thelongitudinal bore at the first end region, a tube, which has a first endportion disposed in the longitudinal bore at the second end region andan oppositely disposed second end region, and a spring disposed in thebore between the ferrule assembly and the tube. The tube defines apassage. The carrier includes a connector end engaged with the connectorand an oppositely disposed cable end, a termination region disposedbetween the connector end and the cable end, a fiber support regiondisposed between the connector end and the termination region forsupporting the optical fiber, and a take-up region disposed between theconnector end and the fiber support region.

A variety of additional inventive aspects will be set forth in thedescription that follows. The inventive aspects can relate to individualfeatures and to combinations of features. It is to be understood thatboth the forgoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the broad inventive concepts upon which the embodiments disclosedherein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present invention and are incorporated in andconstitute a part of this specification. The drawings illustrateexemplary embodiments of the present invention and together with thedescription serve to further explain the principles of the invention.Other aspects of the present invention and many of the attendantadvantages of the present invention will be readily appreciated as thepresent invention becomes better understood by reference to thefollowing Detailed Description when considered in connection with theaccompanying drawings, and wherein:

FIG. 1 is a perspective view of a fiber optic connector assembly made inaccordance with the present invention.

FIG. 2 is an exploded view of the fiber optic connector assembly of FIG.1.

FIG. 3 is a cross-sectional view of the fiber optic connector assemblytaken on line 3-3 of FIG. 1.

DETAILED DESCRIPTION

Reference will now be made in detail to the exemplary aspects of thepresent invention that are illustrated in the accompanying drawings.Wherever possible, the same reference numbers will be used throughoutthe drawings to refer to the same or like parts.

Referring now to FIG. 1, a fiber optic connector assembly, generallydesignated 11, for use in field terminating an optical fiber or opticalfibers is shown. The fiber optic connector assembly 11 includes acarrier, generally designated 13, and at least one connector, generallydesignated 15. While the connector 15 of the subject embodiment of thepresent invention will be described with regard to an LX.5 connector,which has been described in detail in U.S. Pat. Nos. 5,883,995 and6,142,676 and hereby incorporated by reference, it will be understood bythose skilled in the art that the scope of the present invention is notlimited to the use of an LX.5-type connector. While the teachings of thepresent invention could be used with one or more connectors 15, thesubject embodiment of the present invention will be described as havingtwo connectors without intending any limitations on the scope of thepresent invention.

Referring now to FIG. 2, the carrier 13 will be described. The carrier13 includes a connector end 17 and a cable end 19, which is oppositelydisposed from the connector end 17. In the subject embodiment, theconnector end 17 defines slots 23 for mounting the connectors 15. Itwill be understood by those skilled in the art, however, that the scopeof the present invention is not limited to the carrier 13 defining slots23 for mounting the connectors 15. Disposed between the connector end 17and the cable end 19 of the carrier 13 is a fiber support region 25. Inthe subject embodiment, the fiber support region 25 includes guide ways27 that narrow as the depth of the guide ways 27 in the fiber supportregion 25 increase. The carrier 13 further defines a take-up region 29,the purpose of which will be described subsequently, that is disposedbetween the connector end 17 and the fiber support region 25.

A termination region, generally designated 31, is disposed between thecable end 19 of the carrier 13 and the fiber support region 25. Thetermination region 31 of the carrier 13 defines guide paths 33 that aregenerally aligned with the guide ways 27 and crimp tube holes 35 definedby the cable end 19. In the subject embodiment, the guide paths 33narrow as the depth of the guide paths 33 in the termination region 31increase. The termination region 31 further defines a cavity 37. Thecavity 37 is adapted to receive a V-groove chip, generally designated39.

The V-groove chip 39 in the fiber optic connector assembly 11 serves asthe location for the termination of the cleaved optical fibers 41. TheV-groove chip 39 includes a base 43 and a cover 45. The base 43 definesV-grooves 47 that support the cleaved optical fibers 41. Cones 49 aredisposed on either side of the V-grooves 47 in order to assist in theinsertion of the cleaved optical fibers 41 into the V-grooves 47. In thesubject embodiment, the base 43 is made of a silicon material while thecover 45 is made of a transparent material such as pyrex. The cover 45is bonded to the base 43.

The termination region 31 in the carrier 13 includes an adhesive region51 disposed between the cavity 37 and the cable end 19. Disposed in theadhesive region 51 is a heat responsive adhesive element, generallydesignated 53, and a saddle assembly, generally designated 55. In thesubject embodiment, the heat responsive adhesive element 53 is a gluepellet 53. The glue pellet 53 is shown as being generally rectangular inshape, although it will be understood by those skilled in the art thatthe scope of the present invention is not limited to the glue pellet 53being rectangular in shape. The glue pellet 53 includes a first surface57 and an oppositely disposed second surface 59. At least one pathway 61is pre-formed in the glue pellet 53. In the subject embodiment, the atleast one pathway 61 is a channel 61 that is pre-formed in the secondsurface 59 of the glue pellet 53. In the preferred embodiment, twochannels 61 are pre-formed in the second surface 59. The channels 61 areadapted to receive a portion of the cleaved optical fibers 41 and aportion of buffers 63, which surround the cleaved optical fibers 41. Inthe subject embodiment, each of the channels 61 is arcuately shaped soas to conform to the outer surface of the buffers 63.

In the subject embodiment, the saddle assembly 55 includes a saddle,generally designated 65, and a resistor 67. The glue pellet 53 is inthermally conductive contact with the saddle 65, which is in thermallyconductive contact with the resistor 67. In the subject embodiment, thefirst surface 57 of the glue pellet 53 is in contact with a bottomsurface 69 of the saddle 65, thereby establishing the thermallyconductive contact between the glue pellet 53 and the saddle 65. Theresistor 67 is in contact with a top surface 71 of the saddle 65,thereby establishing the thermally conductive contact between theresistor 67 and the saddle 65. A portion of the outer surface of eachbuffer 63 is disposed in channels 61 of the glue pellet 53. In thesubject embodiment, nearly half of the outer circumference of the outersurface of the buffers 63 is disposed in the channels 61.

The carrier 13 further includes crimp tubes 73, which are engaged withthe cable end 19 of the carrier 13. In the subject embodiment, the crimptubes 73 are in a press-fit engagement with the crimp tube holes 35 inthe cable end 19 of the carrier 13. The crimp tubes 73 definepassageways 75 through which the cleaved optical fibers 41 are inserted.Strength members/layers (e.g., Kevlar) of a fiber optic cable can becrimped outside the crimp tube 73 for securing the fiber optic cable.

Referring now to FIG. 3, the connector 15 will be described. Theconnector 15 includes a main body 77 having a front end region 79 and anoppositely disposed back end region 81. The main body 77 defines alongitudinal bore 83, with an inner diameter D₃, that extends throughthe front and back end regions 79, 81. A ferrule assembly, generallydesignated 85, includes a ferrule 87, an optical fiber 89, a portion ofwhich is housed in the ferrule 87, and a hub 91 having a flange 93connectedly engaged with the ferrule 87. The ferrule assembly 85 isdisposed in the longitudinal bore 83 of the connector 15 such that theferrule 87 is positioned in the front end region 79 of the main body 77.

The connector 15 further includes a tube, generally designated 95. Thetube 95 has a first end portion 97 and an oppositely disposed second endportion 99 and defines a passage 101 through the tube 95. The first endportion 97 of the tube 95 is connectedly engaged with the longitudinalbore 83 at the back end portion 81 of the main body 77. In the subjectembodiment, the connected engagement between the tube 95 and the mainbody 77 is a press-fit engagement. In the subject embodiment, an innerdiameter D₁ of the passage 101 at the first end portion 97 of the tube95 is smaller than an inner diameter D₂ of the passage 101 at the secondend portion 99. The purpose for the difference in the inner diametersD₁, D₂ of the passage 101 between the first and second end portions 97,99, respectively, will be described subsequently. The tube 95 furtherincludes an annular groove 103 disposed in the outer surface of the tube95 between the first end portion 97 and the second end portion 99.

Disposed between the ferrule assembly 85 and the tube 95 is a spring105. A first end 107 of the spring 105 abuts the flange 93 of the hub 91while an oppositely disposed second end 109 of the spring 105 abuts anend surface 111 (i.e., a spring stop) of the first end portion 97 of thetube 95. While the spring 105 biases the ferrule assembly 85 toward thefront end region 79 of the main body 77, the spring 105 allows for axialmovement of the ferrule assembly 85 within the longitudinal bore 83(i.e., a spring cavity). In the subject embodiment, and by way ofexample only, the spring 105 allows for at least 1 mm of axial movementof the ferrule assembly 85.

With the ferrule assembly 85, tube 95, and spring 105 disposed in themain body 77, the connector 15 can be connected to the carrier 13. Toconnect the connector 15 to the carrier 13, the connector 15 is insertedinto the slot 23 of the carrier 13 such that the slot 23 is disposed inthe annular groove 103 of the tube 95. In the subject embodiment, theannular groove 103 is in a press-fit engagement with the slot 23. Withthe connector 15 engaged with the carrier 13, dust boots 112 areinserted over fiber ends 113 of the optical fibers 89, which extendthrough the longitudinal bore 83 of the main body 77 and the passage 101of the tube 95. The dust boots 112 are in tight-fit engagement with thesecond end portion 99 of the tube 95. The fiber ends 113 of the opticalfibers 89 are then inserted through the cones 49 of the V-groove chip 39and into the V-grooves 47. With the fiber ends 113 of the optical fibers89 inserted into the V-grooves 47 of the V-groove chip 39, the opticalfibers 89 are secured to the guide ways 27 of the fiber support region25. In the subject embodiment, the optical fibers 89 are affixed to theguide ways 27 with an epoxy thereby forming a fiber constraint 28. Theaffixation of the optical fibers 89 in the guide ways 27 prevents thefiber ends 113 of the optical fibers 89 from moving axially within theV-grooves 47 of the V-groove chip 39.

As stated previously, the spring 105 allows the ferrule assembly 85 tomove axially within the longitudinal bore 83 of the main body 77 towardthe carrier 13. With the optical fibers 89 affixed to the guide ways 27of the fiber support region 25, the axial movement of the ferruleassembly 85 causes the optical fibers 89 to bend between the fibersupport region 25 and the ferrule 87. However, if this bend has a radiusthat is smaller than the minimum recommended bend radius of the opticalfibers 89, damage to the optical fibers 89 will result.

Two dimensions in the fiber optic connector assembly 11 are important inensuring that the optical fibers 89 do not have a bend radius belowminimum recommendations. The first dimension is the inner diameter D₂ ofthe passage 101 (i.e., a fiber take-up cavity). As the inner diameter D₂of the passage 101 decreases, the number of bends in the optical fiber89 increases. However, as the number of bends increase, the radii ofeach bend in the optical fiber 89 decreases. Therefore, there is adirectly proportional relationship between the inner diameter D₂ of thepassage 101 (i.e., the fiber take-up cavity) and the bend radius in theoptical fiber 89. The second dimension is a length L of the take-upregion 29. As the length L increases, the radii of the bends of theoptical fibers 89 increases. Therefore, there is a directly proportionalrelationship between the length L and the bend radius of the opticalfiber 89.

In the subject embodiment, the inner diameter D₂ of the passage 101(i.e., the fiber take-up cavity) must be sized appropriately to accountfor the axial movement of the ferrule assembly 85 and the length L ofthe take-up region 29. If the length L of the take-up region 29 is long,the inner diameter D₂ of the passage 101 (i.e., the fiber take-upcavity) can be smaller since the bend radius of the optical fibers 89will be large. On the other hand, if the length L of the take-up region29 is short, the inner diameter D₂ of the passage 101 (i.e., the fibertake-up cavity) must be larger to avoid the bend radius of the opticalfibers 89 being below the minimum recommendations.

As stated previously, the spring 105 abuts the end surface 111 (i.e.,the spring stop) of the first end portion 97 of the tube 95. In order tohave a proper surface against which the spring 105 would act, the endsurface 111 of the first end portion 97 of the tube 95 must havesufficient surface area to support the spring 105. Therefore, in orderto provide a sufficient surface area to support the spring 105, theinner diameter of the passage 101 should be small. As stated above, theinner diameter D₂ of the passage 101 could be reduced if the length L ofthe take-up region 29 was sufficiently long. This would result, however,in the fiber optic connector assembly 11 having a longer overall length,which is not desirable in some applications. Therefore, the subjectembodiment resolves this dimensional conflict by having the innerdiameter D₁ at the first end portion 97 of the tube 95 smaller than theinner diameter D₂ at the second end portion 99 of the tube 95 therebyforming a necked-down opening 102. In the subject embodiment, and by wayof example only, with the ferrule assembly 85 having an axial movementof at least 1 mm in the longitudinal bore 83, the inner diameter D₁ isabout 950 μm while the inner diameter D₂ is about 3 mm (or about threetimes greater than the inner diameter D₁). By having the inner diameterD₂ at the second end portion 99 of the tube 95 larger than the innerdiameter D1 at the first end portion 97 of the tube 95, the fiber opticconnector assembly 11 can be more compact.

Referring now to FIGS. 2 and 3, the use of the fiber optic connectorassembly 11 for a field termination will be described. With theconnector 15 engaged to the carrier 13, the optical fiber 89 affixed inthe guide way 27 of the fiber support region 25, and the fiber ends 113inserted into the V-groove 47 of the V-groove chip 39, a cleaved end 115of the cleaved optical fiber 41 is inserted into the passageway 75 ofthe crimp tube 73. The cleaved end 115 of the cleaved optical fiber 41is inserted through the channel 61 of the glue pellet 53 and into theV-groove 47 of the V-groove chip 39. In the subject embodiment, an indexmatching gel is disposed between the cleaved end 115 of the cleavedoptical fiber 41 and the fiber end 113 of the optical fiber 89. Theindex matching gel has an index of refraction that matches the index ofrefraction of the glass of the optical fiber 89 and the cleaved opticalfiber 41.

With the cleaved end 115 of the cleaved optical fiber 41 inserted intothe V-groove 47, optical radiation is passed through the optical fibers89 to assess proper alignment of the fiber end 113 and the cleaved end115. If optical radiation is detectable at the junction of the fiber end113 and the cleaved end 115 as viewed through the transparent cover 45of the V-groove chip 39, then the alignment/abutment is not correct. Thecleaved end 115 may have to be polished or cleaned and reinserted intothe V-groove 47. If little to no radiation is detectable at the junctionof the fiber end 113 and the cleaved end 115, then the cleaved opticalfiber 41 and the buffer 63 can be secured to the fiber optic connectorassembly 11 by the glue pellet 53. To secure the cleaved optical fiber41 and the buffer 63 to the fiber optic connector assembly 11, anelectrical power source is connected to the resistor 67. Electricalcurrent is passed through the resistor 67 which heats up the glue pellet53 by way of the thermally conducting saddle 65. As the glue pellet 53heats up, the glue pellet 53 becomes tacky and adheres to the buffer 63and the cleaved optical fibers 41 and closes passageways 75 of the crimptubes 73. When the current is interrupted, the glue pellet 53 resets tosecure the buffers 63 and the cleaved optical fibers 41 in their correctposition in alignment with the optical fibers 89.

With the cleaved optical fibers 41 secured, the fiber optic connectorassembly 11 can be provided as an insert for a housing to protect thefiber optic connector assembly 11 from damage. One housing in which thefiber optic connector assembly 11 can be inserted is described in U.S.Pat. No. 7,490,994, hereby incorporated by reference.

Various modifications and alterations of this invention will becomeapparent to those skilled in the art without departing from the scopeand spirit of this invention, and it should be understood that thisinvention is not to be unduly limited to the illustrative embodimentsset forth herein.

1. A fiber optic connector assembly comprising: a carrier having a firstend, an oppositely disposed second end, a termination region disposedbetween the first end and the second end, and a take-up region disposedbetween the first end and the termination region, wherein the take-upregion is adapted to allow for axial movement of an optical fiber.
 2. Afiber optic connector assembly as claimed in claim 1, wherein thetake-up region allows for at least 1 mm of axial movement of the opticalfiber.
 3. A fiber optic connector assembly as claimed in claim 1,wherein the take-up region is adapted to receive a dust boot forcovering a portion of the optical fiber.
 4. A fiber optic connectorassembly as claimed in claim 1, further comprising a connector adaptedfor engagement with the first end of the connector, the connector havinga main body with a ferrule assembly disposed in the main body, theferrule assembly being adapted for axial movement within the main bodyand having the optical fiber mounted therein.
 5. A fiber optic connectorassembly as claimed in claim 4, wherein the connector includes apassage.
 6. A fiber optic connector assembly as claimed in claim 5,wherein an inner diameter of the passage increases as the passageextends away from the ferrule assembly.
 7. A fiber optic connectorassembly as claimed in claim 6, wherein the passage is defined by a tubehaving a first end region and an oppositely disposed second end region,the tube being disposed in a longitudinal bore defined by the main bodyof the connector.
 8. A fiber optic connector assembly as claimed inclaim 7, wherein the second end region of the tube extends outwardlyfrom the main body of the connector and is adapted for engagement withthe first end of the carrier.
 9. A fiber optic connector assembly asclaimed in claim 7, wherein a spring is disposed in the longitudinalbore between the ferrule assembly and the first end region of the tube.10. A fiber optic connector assembly as claimed in claim 9, wherein theinner diameter of the passage of the tube at the first end region isabout 950 μm.
 11. A fiber optic connector assembly as claimed claim 10,wherein the inner diameter of the passage of the tube at the second endregion is about 3 mm.
 12. A fiber optic connector assembly as claimed inclaim 4, wherein the carrier includes a fiber support region disposedbetween the termination region and the first end.
 13. A fiber opticconnector assembly as claimed in claim 12, wherein the optical fiber isaffixed to a guide way of the fiber support region.
 14. A fiber opticconnector assembly as claimed in claim 13, wherein the optical fiber isaffixed to the guide way by epoxy.
 15. A fiber optic connector assemblyas claimed in claim 14, wherein the guide way narrows as the depthincreases.
 16. A fiber optic connector assembly as claimed in claim 1,further comprising a V-groove chip disposed in the termination region ofthe carrier.
 17. A fiber optic connector assembly as claimed in claim 1,further comprising a heat responsive adhesive element disposed in thetermination region of the carrier.
 18. A fiber optic connector assemblyas claimed in claim 17, wherein the heat responsive adhesive element haspathways for receiving an cleaved optical fiber and buffer.
 19. A fiberoptic connector assembly as claimed in claim 18, wherein the pathwaysare channels disposed on a surface of the heat responsive adhesiveelement.
 20. A fiber optic connector assembly as claimed in claim 17,wherein a saddle assembly is disposed in the termination region andengaged with the heat responsive adhesive element.
 21. A fiber opticconnector assembly as claimed in claim 1, wherein the second end definesa crimp tube hole that is adapted to receive a crimp tube.
 22. A fiberoptic connector assembly comprising: a connector defining a longitudinalbore extending through the connector and having a first end region andan oppositely disposed second end region, a ferrule assembly at leastpartially disposed in the longitudinal bore at the first end regionhaving an optical fiber that extends through the connector, a tubehaving a first end portion disposed in the longitudinal bore at thesecond end region and an oppositely disposed second end portion, aspring disposed in the bore between the ferrule assembly and the tube,wherein the tube defines a passage; and a carrier having a connector endengaged with the connector and an oppositely disposed cable end, atermination region disposed between the connector end and the cable end,a fiber support region disposed between the connector end and thetermination region for supporting the optical fiber, and a take-upregion disposed between the connector end and the fiber support region.23. A fiber optic connector assembly as claimed in claim 21, wherein aninner diameter of the passage of the tube at the first end portion issmaller than an inner diameter of the passage of the tube at the secondend portion.
 24. A fiber optic connector assembly as claimed in claim21, further comprising a dust boot disposed over the optical fiberbetween the fiber support region and the connector end.
 25. A fiberoptic connector assembly as claimed in claim 21, further comprising aV-groove chip disposed in the termination region of the carrier.
 26. Afiber optic connector assembly as claimed in claim 21, furthercomprising a heat responsive adhesive element disposed in thetermination region of the carrier. 27-31. (canceled)